Fire prevention and explosion protection systems MCQs With Answer

Fire prevention and explosion protection systems MCQs With Answer

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Introduction:

This quiz collection on Fire Prevention and Explosion Protection Systems is designed specifically for M.Pharm students studying Hazards and Safety Management. It covers core principles—fire chemistry, ignition sources, combustible dust and vapor hazards—as well as practical protective measures such as intrinsic safety, explosion venting, suppression, inerting, bonding and grounding, and regulatory standards (e.g., ATEX, NFPA). Questions focus on concepts you will encounter in pharmaceutical facilities where powders, solvents and confined spaces increase risk. Use these MCQs to test and deepen your understanding of prevention strategies, detection and control technologies, and safe design choices required to minimize fire and explosion hazards in pharmaceutical operations.

Q1. Which of the following best describes the ‘fire triangle’ concept used in fire prevention?

  • Fuel, oxygen, heat
  • Ignition temperature, pressure, time
  • Combustible dust, spark energy, humidity
  • Ventilation, suppression, isolation

Correct Answer: Fuel, oxygen, heat

Q2. Which fire class primarily applies to flammable liquids commonly used in pharmaceutical labs (e.g., ethanol)?

  • Class A
  • Class B
  • Class C
  • Class D

Correct Answer: Class B

Q3. The Lower Explosive Limit (LEL) indicates:

  • The maximum concentration of vapor that will burn
  • The minimum concentration of vapor in air that can propagate flame
  • The temperature at which a vapor auto-ignites
  • The energy required to ignite a vapor cloud

Correct Answer: The minimum concentration of vapor in air that can propagate flame

Q4. Which test method is commonly used to measure flash point of solvents in pharmaceutical settings?

  • Pensky-Martens closed cup
  • Bomb calorimeter
  • Burning rate test
  • Leidraad open pan

Correct Answer: Pensky-Martens closed cup

Q5. Intrinsic safety (IS) protection is best described as:

  • A method that encloses equipment to prevent sparks leaving the enclosure
  • A technique that limits electrical energy to below ignition-capable levels
  • A grounding system to remove static charges
  • A ventilation strategy to keep solvent vapors below LEL

Correct Answer: A technique that limits electrical energy to below ignition-capable levels

Q6. Which regulation or directive is primarily concerned with equipment in explosive atmospheres in the European Union?

  • OSHA 1910
  • ATEX
  • REACH
  • ISO 9001

Correct Answer: ATEX

Q7. In dust explosion theory, which additional element completes the “fire triangle” to form the “dust explosion pentagon”?

  • Humidity and light
  • Spark energy and pressure
  • Dispersion and confinement
  • Temperature and oxygen

Correct Answer: Dispersion and confinement

Q8. Which of the following is the main purpose of explosion venting panels in process equipment?

  • To extinguish the flame using foam
  • To relieve pressure and direct the blast to a safe area
  • To filter released gases before discharge
  • To prevent ingress of moisture into equipment

Correct Answer: To relieve pressure and direct the blast to a safe area

Q9. What is the primary function of an explosion isolation system (e.g., fast-acting valves or rotary valves) on conveyors?

  • To clean dust from the conveyor belt
  • To prevent flame and pressure propagation to other units
  • To cool conveyed material below ignition temperature
  • To dehumidify material to reduce static

Correct Answer: To prevent flame and pressure propagation to other units

Q10. Which suppression agent is commonly used as a clean fire extinguishing gas suitable for sensitive pharmaceutical areas?

  • Carbon dioxide (CO2)
  • FM-200 (heptafluoropropane)
  • Foam AFFF
  • Dry chemical (monoammonium phosphate)

Correct Answer: FM-200 (heptafluoropropane)

Q11. Minimum Ignition Energy (MIE) is most relevant when assessing the hazard of which material in pharmaceutical manufacture?

  • Compressed gases like oxygen
  • Bulk solvents in closed tanks
  • Combustible powders and dusts
  • Corrosive liquids

Correct Answer: Combustible powders and dusts

Q12. Which statement correctly distinguishes deflagration from detonation?

  • Deflagration travels at supersonic speed; detonation is subsonic
  • Deflagration is a slow oxidation; detonation involves a shock wave and supersonic propagation
  • Deflagration requires confinement; detonation occurs only in open air
  • They are the same phenomenon described in different standards

Correct Answer: Deflagration is a slow oxidation; detonation involves a shock wave and supersonic propagation

Q13. Which control measure reduces the risk of electrostatic ignition during transfer of flammable solvents?

  • Increase solvent temperature
  • Use plastic hoses for insulation
  • Implement bonding and grounding of containers and equipment
  • Store solvents in sealed glass bottles only

Correct Answer: Implement bonding and grounding of containers and equipment

Q14. In an inerting system for a reactor handling flammable solvents, which gas is most commonly used to lower oxygen concentration?

  • Oxygen
  • Nitrogen
  • Hydrogen
  • Argon

Correct Answer: Nitrogen

Q15. NFPA 68 and NFPA 69 primarily address which aspects of explosion protection?

  • Material safety data sheet formatting
  • Explosion venting and prevention of deflagrations
  • Emergency medical response for burn injuries
  • Personal protective equipment selection

Correct Answer: Explosion venting and prevention of deflagrations

Q16. What characteristic defines an “explosion-proof” electrical enclosure (often used in hazardous areas)?

  • It contains a sacrificial fuse to blow before sparking
  • It withstands an internal explosion and prevents ignition of the external atmosphere
  • It dissipates heat faster than standard enclosures
  • It is waterproof and dustproof only

Correct Answer: It withstands an internal explosion and prevents ignition of the external atmosphere

Q17. Which parameter is most important when selecting a ventilation strategy to prevent accumulation of solvent vapors?

  • Color of the building walls
  • Air changes per hour to keep vapor concentrations below a safe fraction of LEL
  • Number of personnel in the area regardless of process
  • Type of flooring material

Correct Answer: Air changes per hour to keep vapor concentrations below a safe fraction of LEL

Q18. What is the main advantage of using intrinsic safety barriers for instrumentation in hazardous zones?

  • They eliminate the need for explosion-proof enclosures entirely
  • They allow safe signal transmission by limiting current and energy to non-ignition levels
  • They increase signal power to overcome interference
  • They automatically vent equipment during overpressure

Correct Answer: They allow safe signal transmission by limiting current and energy to non-ignition levels

Q19. Which of the following best describes a “BLEVE” (Boiling Liquid Expanding Vapor Explosion) risk in pharmaceutical storage?

  • An explosion caused by dust cloud ignition
  • An explosive failure of a pressurized vessel containing a flammable liquid when heated
  • An electrical arc flash inside an instrument panel
  • A controlled venting of non-flammable gases

Correct Answer: An explosive failure of a pressurized vessel containing a flammable liquid when heated

Q20. Safety Integrity Level (SIL) in a safety instrumented system indicates:

  • The physical size of the safety device
  • The probability of failure on demand and required risk reduction performance
  • The electrical power rating of the system
  • The installation date of the safety system

Correct Answer: The probability of failure on demand and required risk reduction performance

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